Syntax error at select with a subquery join - postgresql

Question

I have a working postgresql query
select * from "A" left join (
select distinct on ("provider_id") * from "B" order by "provider_id" asc, "date" desc
) B using ("provider_id") where "A"."date" >= '2022-02-17T08:31:46.781Z' order by "A"."date" desc limit 25;
How to build the query with knex?
I tried .leftJoin
query
.orderBy("date", orderBy.sort)
.limit(Math.min(limit, 1000))
.offset(Math.min(offset, 100000))
.leftJoin(
this.db('B')
.distinctOn('provider_id')
.select('*')
.orderBy([
{
column: 'provider_id',
},
{
column: 'date',
order: 'desc',
},
]),
'A.provider_id',
'B.provider_id'
)
and .leftJoin + .raw
query
.orderBy("date", orderBy.sort)
.limit(Math.min(limit, 1000))
.offset(Math.min(offset, 100000))
.leftJoin(
this.db.raw('select distinct on ("provider_id") * from "B" order by "provider_id", "date" desc'),
'A.provider_id',
'B.provider_id'
)
but I got the following query generated query.toQuery()
select * from "A" left join select distinct on ("provider_id") * from "B" order by "provider_id", "date" desc on "A"."provider_id" = "B"."provider_id" where "date" >= '2022-02-17T09:09:08.148Z' order by "date" desc limit 25
If I copy it and execute it on DB manually, it throws the error
ERROR: syntax error at or near "select"
LINE 62: select * from "A" left join select distinct on ("provid...
^
SQL state: 42601
Character: 3951
Knex doesn't encapsulate the subquery in () B. That's why it fails.

Answer 1

The key is to remember that raw is raw. You can use any valid query syntax in .raw including subqueries, parenthesis, aliases, etc.
You can hook up the left join subquery to the existing knex query object in the following way
query.leftJoin(
this.db.raw(
`(select distinct on ("provider_id") * from "B" where "date" >= '2022-02-17T14:45:27.827Z' order by "provider_id", "date" desc limit 10000) B`
),
'A.provider_id',
'B.provider_id'
)
The produced query example:
select a_field as aField from "A" left join (select distinct on ("provider_id") * from "B" where "date" >= '2022-02-17T14:45:27.827Z' order by "provider_id", "date" desc limit 10000) B on "A"."provider_id" = "B"."provider_id" where "A"."created_at" >= '2022-02-17T14:44:12.800Z' order by "A"."created_at" desc limit 25